The present invention relates generally to prosthetic devices, and more particularly to a prosthetic-limb coupling-socket adapter which secures a boss of a prosthetic-limb link-member.
As shown in FIG. 1a, a conventional pyramidal link-plate 10 is one type of prosthetic-limb link-member and has a frustopyramidal, four-sided boss 12 projecting from a dome-shaped, or a spherically-convex-shaped, base 14, which in turn projects from a plate member 16. The plate member 16 will typically include four screw or bolt-receiving, through-holes 18 corresponding to a standard (within the industry) four-hole pattern.
As shown in FIG. 1b, a prosthetic limb 20 for a transfemoral amputee will include a prosthetic limb socket 22 for receiving the wearer""s residual limb, a knee joint assembly 24, a first pylon component 23 between the prosthetic limb socket and the knee joint assembly, interconnection components 26 for coupling the first pylon 23 to the prosthetic limb socket 22, interconnection components 27 for coupling the first pylon to the knee joint assembly 24, an ankle/foot assembly 28, and a second pylon 29 coupled between the knee joint assembly 24 and the ankle/foot assembly 28. The interconnection components 26 may consist of a locking or suction assembly 30 (such as a Shuttle Lock component or a ProSeal component commercially available from Prosthetic Design, Inc.) positioned within a distal end of the prosthetic limb socket 22, the conventional pyramidal link-plate 10, and a conventional coupling-socket adapter 32 for coupling the first pylon 23 to the distal boss 12 of the pyramidal link-plate 10. Likewise, the interconnection components 27 may consist of another conventional pyramidal link-plate 10 mounted to the knee-joint assembly and another conventional coupling-socket adapter 32 for coupling the first pylon 23 to the distal boss 12 of the pyramidal link-plate 10. A plurality of set screws 33 extend radially and downwardly against the distal boss 12 of the pyramidal link-plate 10 and are tightened to securely mount the pyramidal link-plate 10 (and the respective prosthetic limb components fastened thereto) to the coupling-socket adapter 32 (and the first pylon 23). The conventional pyramidal link-plate 10 and the conventional coupling-socket adapter 32 are primarily based upon the xe2x80x9cAdjustable Linkxe2x80x9d described in U.S. Pat. No. 3,659,294 to Glabiszewski, the disclosure of which is incorporated herein by reference.
In fitting prosthetic limbs to patients, it is often necessary for the prosthetist to modify the alignments and orientations of the various prosthetic limb components with respect to each other during the initial fitting or after the patient has worn the prosthetic limb for a period of time. The first pylon 23 is typically capable of being rotatably adjusted with respect to the coupling-socket adapters. However, with certain transfemoral amputees, the distance between the distal end of the patient""s residual limb and the patient""s natural knee center is very short; and if the combined length of the components between a prosthetic limb socket and the prosthetic knee joint is greater than the distance between the distal end of the patients residual limb and the patient""s natural knee center, then the prosthetist may be forced to eliminate the first pylon 23. Otherwise the knee center on the prosthetic side will be too low, thus causing gate deviation.
When the first pylon 23 is eliminated, the means to rotatably adjust the various prosthetic limb components is also lost. Accordingly, there are existing pyramidal link-plate components which offer sliding and/or rotating capabilities to such components. The disadvantage with the conventional sliding and/or rotating pyramidal link-plate components is that, to provide such adjustability, the profile and/or the length of the component must be increased. Other rotatably adjustable pyramidal link-plate components only allow finite or incremental rotation and are difficult to adjust.
For example, one known rotatably adjustable pyramidal link-plate assembly includes a dome shaped component having the pyramidal boss extending from its apex, where the dome shaped component includes an upwardly facing (i.e., facing in towards the apex of the dome), serrated, annular ring positioned around an outer circumference of the base of the dome. The assembly also includes a planar base plate component having four screw-holes extending therethrough and arranged in a standard four-hole pattern. The planar base plate also has a central hole sized for receiving the dome portion of the dome shaped component therethrough. On the underside of the planar base plate, encircling the central hole, is a serrated, annular ring adapted to engage with the upwardly facing serrated, annular ring of the dome shaped component when the dome shaped component is inserted through the underside of the central hole. When the two components are assembled, and installed onto a prosthetic limb component by tightening four screws extending through the screw-holes, the two components are rotationally locked with respect to each other. To rotatably adjust the two components with respect to each other, the four screws must be loosened enough to allow the base plate component to be lifted from the dome shaped component to a sufficient extent so that the two serrated rings disengage from one another. Once the rotational adjustment is made, the screws are tightened again.
One disadvantage with this design is that the serrations, or teeth, allow for only finite (e.g. 5 or 6 degree increments) rotational adjustments. Additionally, it is often-times difficult to have access to the four screws extending through the base plate component (especially when the prosthetic limb socket and knee joint assembly are positioned in close proximity to one another). To access the four screws in such a situation, the adjustable pyramid link-plate assembly must first be separated from the female coupling-socket adapter. Accordingly the prosthetist will essentially have to disassemble the prosthetic limb to adjust rotational alignment.
Accordingly, there is a need for a prosthetic-limb coupling-socket adapter assembly that provides rotatable adjustment for the prosthetic limb, yet does not significantly increase the profile or length of the attachment of the interconnection components. There also is a need for a prosthetic-limb coupling-socket adapter assembly that provides for infinite rotational adjustments. There further is a need for a prosthetic-limb coupling-socket adapter assembly that does not require disassembly of the various interconnection components to allow for rotational adjustments.
In a first statement of the coupling-socket adapter assembly of the invention, the coupling-socket adapter assembly is for a prosthetic limb and includes a base plate subassembly, a coupling-socket adapter, and a rotational locking and unlocking mechanism. The base plate subassembly is attachable to a first prosthetic limb component. The coupling-socket adapter is rotatably attached to the base plate subassembly and has a cavity for receiving a male coupling member (such as a boss of a pyramidal link-plate). The mechanism locks the coupling-socket adapter against rotation with respect to the base plate subassembly and unlocks the coupling-socket adapter for rotation with respect to the base plate subassembly. The mechanism is operable when the base plate subassembly is attached to the first prosthetic limb component.
In a second statement of the coupling-socket adapter assembly of the invention, the coupling-socket adapter assembly is for a prosthetic limb and includes a base plate subassembly, a coupling-socket adapter, and a ring. The base plate subassembly is attachable to a first prosthetic limb component. The coupling-socket adapter is rotatably attached to the base plate subassembly, has an upper portion and a lower portion, and has a cavity for receiving a male coupling member (such as a boss of a pyramidal link-plate). The ring surrounds the lower portion of the coupling-socket adapter, is positioned between the base plate subassembly and the upper portion of the coupling-socket adapter, and is threadably engaged with the base plate subassembly or the coupling-socket adapter or both. Rotation of the ring locks the coupling-socket adapter against rotation with respect to the base plate subassembly, and counterrotation of the ring unlocks the coupling-socket adapter for rotation with respect to the base plate subassembly.
In a third statement of the coupling-socket adapter assembly of the invention, the coupling-socket adapter assembly is for a prosthetic limb and includes a base plate subassembly, a coupling-socket adapter, and a ring. The base plate subassembly is attachable to a first prosthetic limb component. The coupling-socket adapter is rotatably attached to the base plate subassembly, has an upper portion and a lower portion, and has a cavity for receiving a male coupling member (such as a boss of a pyramidal link-plate). The ring surrounds, and is threadably attached to, the lower portion of the coupling-socket adapter, and the ring is positioned between the base plate subassembly and the upper portion of the coupling-socket adapter. Rotation of the ring with respect to the coupling-socket adapter locks the coupling-socket adapter against rotation with respect to the base plate subassembly, and counterrotation of the ring with respect to the coupling-socket adapter unlocks the coupling-socket adapter for rotation with respect to the base plate subassembly.
In a fourth statement of the coupling-socket adapter assembly of the invention, the coupling-socket adapter assembly is for a prosthetic limb and includes a base plate subassembly, a coupling-socket adapter, and an adjustable-diameter ring-clamp. The base plate subassembly is attachable to a first prosthetic limb component. The coupling-socket adapter is rotatably attached to the base plate subassembly, has an upper portion and a lower portion, and has a cavity for receiving a male coupling member (such as a boss of a pyramidal link-plate). The lower portion includes a tapered outside circumferential surface. The ring-clamp is positioned between the base plate subassembly and the upper portion of the coupling-socket adapter and has a tapered inside circumferential surface which surrounds the tapered outside circumferential surface of the lower portion of the coupling-socket adapter. Decreasing the diameter of the ring clamp locks the coupling-socket adapter against rotation with respect to the base plate subassembly, and increasing the diameter of the ring-clamp unlocks the coupling-socket adapter for rotation with respect to the coupling-socket adapter.
In a fifth statement of the coupling-socket adapter assembly of the invention, the coupling-socket adapter assembly is for a prosthetic limb and includes a base plate subassembly, a coupling-socket adapter, a threaded fastener, and a rotational locking and unlocking mechanism. The base plate subassembly is attachable to a first prosthetic limb component and includes a tapered hole having a longitudinal axis and a tapered side wall. The coupling-socket adapter has a cavity for receiving a male coupling member (such as a boss of a pyramidal link-plate). The threaded fastener has a tapered portion positioned in the tapered hole and is threadably attached to the coupling-socket adapter so that the coupling-socket adapter is rotatably attached to the base plate subassembly. The mechanism longitudinally moves the threaded fastener, in a first direction, into frictional-locking engagement with the tapered side wall for locking the coupling-socket adapter against rotation with respect to the base plate subassembly. The mechanism moves the threaded fastener, in a direction opposite to the first direction, out of frictional-locking engagement with the tapered side wall for unlocking the coupling-socket adapter for rotation with respect to the base plate subassembly. The mechanism is operably when the base plate subassembly is attached to the first prosthetic limb component.
In a sixth statement of the coupling-socket adapter assembly of the invention, the coupling-socket adapter assembly is for a prosthetic limb and includes a base plate subassembly, a coupling-socket adapter, and a threaded press. The base plate subassembly is attachable to a first prosthetic limb component. The coupling-socket adapter is positioned adjacent to the base plate subassembly. One of the base plate subassembly and the coupling-socket adapter includes a conical cavity that widens with the distance from the other one of the base plate subassembly and the coupling-socket adapter. The other one of the base plate subassembly and the coupling-socket adapter includes a conical projection extending therefrom and into the conical cavity, the conical projection widens with the distance from the other one of the base plate subassembly and the coupling-socket adapter. The threaded press is operative to push the base plate subassembly away from the coupling-socket adapter, thereby causing the conical projection to frictionally lock against the inner surface of the conical cavity, whereby the coupling-socket adapter is rotatable with respect to the base plate subassembly when the threaded press is deactivated, but is rotationally locked with respect to the base plate subassembly when the threaded press is activated.
Preferably, for each coupling-socket adapter assembly described in the previous six paragraphs, the base plate subassembly includes a base plate, a slide plate, and a slide locking and unlocking device. The base plate is attachable to the first prosthetic limb component and has a rectilinear surface groove. The slide plate is slidably captured in the surface groove, and the coupling-socket adapter is rotatable attached to the slide plate. The device locks the slide plate against sliding in the surface groove and unlocks the slide plate for sliding in the surface groove. The device is operable when the base plate is attached to the first prosthetic limb component.
Several benefits and advantages are derived from the invention. Rotatably attaching a coupling-socket adapter to a base plate subassembly and providing a mechanism, such as the previously-described ring or ring-clamp, allows rotatable adjustment, including infinite rotational adjustments, for the prosthetic limb while the coupling-socket adapter assembly remains attached to the first prosthetic limb component. The ring does not significantly increase the profile or height of the attachment of the interconnection components. When present, the optional slide plate and optional slide locking and unlocking device of the base plate subassembly allow translational adjustment, including infinite translational adjustment, along a linear axis between two end positions for the prosthetic limb while the coupling-socket adapter assembly remains attached to the first prosthetic limb component.